Experiment and application of grouting reinforcement material for broken coal and rock in roadway

To solve the supporting problem of broken coal and rock in roadway, in view of the characteristics of large depth, high stress and passing through close coal seam of the 226 rail haulage cross-cut of Shanjiaoshu coal mine, through the site investigation and theoretical analysis of 226 rail haulage cross-cut, the deformation and failure characteristics of the roadway are studied, and superfine cement ordinary cement is proposed to be used as grouting material to reinforce the broken crosscut roadway.Based on the uniaxial compression, split test and mercury injection laboratory tests of samples, the mechanical parameters and pore size distribution of pouring slurry with different proportion of superfine cement and water cement ratio are studied.The results show that with the increase of the proportion of superfine cement, the compressive strength and elastic modulus of pouring slurry first increase and then decrease, the porosity decreases, and the void and pore volume ratio increases.According to the data of laboratory tests, the optimal grouting material ratio is determined, and combined with the geological conditions of the surrounding rock, the support scheme of "double layer anchor net+grouting cable anchor" is proposed.On-site monitoring and application of the new grouting support scheme reduced the deformation of the roof and floor by 85% and the deformation of the two gangs by 86%, indicating that the slurry has a good curing effect on the broken surrounding rock roadway.The application of the new grouting support scheme on site reduced the deformation of the top and bottom plates by 85%, and the deformation of the two gangs by 86%,indicating that the slurry has good solidification effect on the broken surrounding rock roadway.